Some people have discussed in specific meta of site but I am asking here the center of every site.
I have seen a question which has good content but got down vote without any reason and one got up vote which is not closed by moderators. Or moderators are doing wrong, or maybe voters are doing wrong.
If person doesn't like a content personally and voting it down or a person think that this content is good for community and given up vote.
What is the exact role of voting